Winding machine



Jan. 13, 1970 H. H. RICHTER WINDING MACHINE 3 Sheets-Sheet 1 Filed Dec. 9, 1966 FIG! (,1 lI'VIIIIIIIIIIIII/ INVENTOR.

FIG.6

Jan; 13, 1970 H. H. RICHTER 3,489,359

WINDING MACHINE Filed Dec. 9, 1966 5 Sheets-Sheet 2 N INVENTOR y ANS H. RICHTER {5 BY 5/ I M ATTORNEYS Jan. 13, 1970 H. H. RICHTER 3,489,359

. WINDING MACHINE Filed Dec. 9, 1966 3 Sheets-Sheet 3 INVENTOR.

HANS H. CHTER BY M z7/az ATTOR N EYS United States Patent C 3,489,359 WINDING MACHINE Hans H. Richter, Cranston, R.I., assignor to Leesona Corporation, Warwick, R.I., a corporation of Massachnsetts Filed Dec. 9, 1966, Ser. No. 600,553 Int. Cl. B6511 57/04 US. Cl. 24243 16 Claims ABSTRACT OF THE DISCLOSURE A winding machine including a traversing mechanism employing a pair of endless belt spans, each of which carries yarn traversing fingers arranged to move in opposite directions to traverse the yarn axially of a winding package. Auxiliary yarn engaging members are positioned to facilitate reversal of the yarn at the package ends. Also, means for controlling tension in the winding yarn and means for controlling the path of the yarn as the yarn advances to the package are disclosed.

This invention relates to yarn winding machinery and more particularly to improved method and apparatus for traversing a strand of yarn onto a take-up package especially at very high speeds.

Throughout the specification and claims the term yarn is intended to include any elongated or strandular material, textile or otherwise, and the term package refers to a wound mass of strand material, whatever its shape.

In recent years, advances in the spinning of synthetic yarns whereby molten filament-forming compositions are extruded through a spinneret into a coagulating medium and thereupon stretched or drawn have made it possible to produce these yarns rapidly in large quantities. In the manufacturing process therefor it is necessary to take up the newly-formed yarn immediately as it advances from the godet or drawing rolls in order to preserve the yarn as an unentangled product. It has been increasingly difficult for conventional Winding machines to take up the yarn and form satisfactory packages at the most economical yarn forming rates consistent with the high production rates of the synthetic yarns.

One of the most significant limitations in the use of known winding machines for taking up yarn advancing at high speeds resides in the difficulties in successfully traversing the yarn to and fro onto the package. One existing type traversing mechanism employs a reversible yarn guide for guiding the yarn. However, this device causes the yarn to dwell momentarily at the reversing points, thereby creating a package of undesirable configurations.

Conventional helically grooved traverse rolls have also been employed to wind yarns at high speeds in redraw operations, but these have not been entirely successful because the helix angle of the yarn wound on the package is constantly changing as the package grows in diameter and this has been found to present certain deficiencies in the wound package.

A further known mechanism for winding yarn onto a take-up package comprises apparatus wherein yarn en gaging fingers su ported on a belt or other elongated, flexible member follow a continuously repeating path at a substantially constant rate of speed such that the fingers are caused to move in opposite directions to distribute the yarn on the package being wound. With this mechanism it is possible to avoid the difficulties imposed by the conventional cam-operated traverse guide and by the usual traverse rolls. For example, the mass of the fingers, although small in any event, is of virtually no consequence because they are not required to reverse direction at the ends of the winding package, Vibrations are minimized ICC because all movements are essentially rotary rather than rec 1procatory, the only mass abruptly changing direction being that of the yarn itself. Also, this latter type of traverse mechanism is capable of winding a precision package wherein the helix angle of the wound yarn is held to a constant value and wherein ribboning is prevented.

The invention herein is an improvement upon the traverse mechanism just described which employs simply an elongated member fitted with guide fingers. A primary difficulty which heretofore resided in continuous trayerses of the so-called endless belt or endless chain type, 1.e., the type just referred to, was the inability of these traverses to maintain a constant tension in the yarn strand as the strand advanced to the take-up package from the supply. Concurrent therewith, it was diflicult to control the strand in the region of yarn reversal. Stitching was a typical consequence of this lack of control. Stitching" refers to that occurrence 'wherein a portion of a yarn strand slides ofi the end of the package from the peripheral surface thereof. High package ends were another undesirable occurrence due to inadequate control of the yarn upon transfer from one finger to another during periods of yarn reversal. The high ends resulted from a delay in the reversal of the yarn at the ends of the package. Each of these deficiencies has been substantially re duced or eliminated by means of the invention herein.

A primary feature of the invention resides in the application to a continuous type traverse of a fluid operated yarn control device located intermediate the supply and the take-up package. The control device serves to compensate for tension variations in the strand as it advances toward the package. It performs by accumulating therewithin excess yarn during a potentially slack period, and by releasing yarn as required during a period of potentially excessive tension. A salient characteristic of the control device resides in its operation whereby the yarn is confined to a strict path as it advances toward and onto the package.

Another feature of the invention resides in the use of auxiliary yarn engaging fingers integral with the pulleys guiding the belts, which auxiliary fingers cooperate with the fingers on the belts to provide continuous yarn control in the region of yarn reversal at the ends of the package. Yet other features of the invention reside in expedients which serve to counteract the formation of a balloon immediately upstream of the package to thereby control the tension in the advancing strand of yarn.

Accordingly, it is an objet of the invention to provide new and improved apparatus for winding yarn onto a take-up package, especially at very high speeds.

Another object of the invention is to provide new and improved apparatus to maintain constantly tensioned an advancing strand of yarn being traversed by fingers which are caused to move continuously in opposite linear directions adajacent the peripheral surface of the take-up package. A related object is to maintain the yarn under substantially constant tension. Another related object is to provide such apparatus having a yarn control device located intermediate the yarn supply and the take-up package to accumulate excess yarn during a potentially slack period and adapted to release the yarn during a period of potentially excessive strand tension to thereby maintain the yarn constantly tensioned.

Still another object of the invention is to provide a new and improved yarn traversing mechanism having side-by-side endless conveyor belt spans travelling in opposite directions for traversing yarn and including apparatus operable to effect accurate control of the yarn in the regions of yarn reversal.

Yet another object of the invention is to provide a new and improved yarn traversing mechanism having side-byside endless conveyor belts travelling in opposite directions, yarn engaging fingers secured to the conveyor belts for traversing yarn, and auxiliary yarn engaging fingers extending radially from belt supporting pulleys at each end of the package, said pulleys introducing the belts along paths adjacent the surface of the package, and said auxiliary finger cooperating with said yarn engaging fingers to control the yarn in the regions of yarn reversal.

Other and further objects and advantages of the invention will be obvious or will appear hereinafter in the description and in the drawings appended hereto.

In the drawings wherein like numerals refer to like parts throughout,

FIG. 1 is a front elevation view schematically illustrating a winding machine incorporating the present invention;

FIG. 2 is a top plan view of the apparatus illustrated in FIG. 1, certain parts being removed for clarity;

FIG. 3 is an enlarged schematic view in elevation illustrating a portion of FIG. 2;

FIG. 4 is an elevation view taken along lines 4-4 of FIG. 2, but with the yarn traversing fingers being shown at their respective positions during yarn reversal as the yarn is transferred from one finger to another;

FIG. 5 is a section view taken along lines 55 of FIG. 4;

FIG. 6 is a top plan view of a modified form of the embodiment illustrated in FIGS. 1 through 5, certain parts being broken away for added clarity;

FIGS. 7A through 7G are views in sequence illustrating the successive relative positions of the cooperating yarn engaging fingers and auxiliary fingers in one region of yarn reversal; and r FIG. 8 is a cross-sectional view taken along lines 8 of FIG. 2 illustrating the mounting for a pair of the guide pulleys.

Referring now to the drawings, and especially to FIG. 1

thereof, a strand of yarn Y is illustrated advancing toward a conventional winding mechanism including a take-up package P, from any suitable supply source. The winding machine embodying the principles of the invention herein is indicated generally by reference numeral 12. As the strand Y is drawn from the supply toward package P at a substantially constant rate, it is intercepted by a fluid-operated guide 16 positioned at an extremity of a tension compensating arm 18. Arm 18 may be of any suitable design, pivotally mounted, for example, so as to move through an are as yarn tension varies and being operable in a known manner to adjust a motor control (not shown) to vary the rotational speed of package P to compensate for changes in tension in strand Y. Guide 16 is preferably of the construction disclosed in the commonly assigned United States application for patent of John V. Keith et al., filed Mar. 25, 1966 and bearing Ser. No. 537,526, now U.S. Patent 3,393,880, granted July 23, 1968. According to the teaching therein, guide 16 is formed with a combination passage and plenum chamber 20 which is sufficiently wide to receive and allow the advance of a strand of yarn while preventing lateral strand movement. A suitable source of pressurized fluid such as compressed air (not illustrated in FIG. 1) is connected to combination passage and plenum chamber 20 through line 21 and the fluid is so directed that it impinges upon the advancing yarn strand and supports it at a distance from the body of guide 16. By so riding on a cushion of fluid in the plenum chamber during its advance, the yarn is firmly, but gently controlled in a substantially friction-free manner. The guide 16 serves to compensate for tension variations resulting from the changing length of strand Y between guide 16 and package P in the course of traversing across the surface thereof and is especially effective to control the tension in the strand at the delicate moment of yarn reversal when the strand is agilely transferred from a yarn engaging finger advancing in one direction across the surface of the package to another oppositely advancing yarn engaging finger. Although the yarn must be firmly controlled at this critical instant, it is necessary that the control be of a gentle nature lest the quality of the package be reduced. The fluid-operated guide 16 offers the firm but gentle control necessary, therefor, and taken in combination with the winding machine 12 employing the continuous belt-type traverse mechanism as next to be described, provides a means heretofore unknown of winding yarn at very high rates of speed into packages of superior form suitable for all known redraw operations.

\ From the guide 16, the yarn strand Y advances to the package P and is carried to and fro lengthwise thereof by a traverse mechanism generally indicated at 22.

With particular reference to FIG. 2, yarn package P is seen in the process of winding on a tube or core 24 which is slidingly received on spindle 26 and clamped in place thereon. The drive shaft 28- of a drive motor M is drivingly connected to the central shaft 30 of spindle 26 via pulleys 32 and 34 and a connecting belt 36 engageably received on said pulleys. A substantially vertical shaft 38 is fixedly mounted on a platform 40 of the winding machine 10, said platform serving as the base of a housing 42 whose cover has been removed (viewing FIG. 2) to provide a clear view of the contents thereof.

As best seen in FIG. 3, pulleys 44a, 44b are integral with pulleys 46a, 46b; respectively and these pulleys are freely rotatable on the shaft 38 and are supported on 30 steps 47 of the shaft. The pulleys 44a, 44b are disposed to drivingly engage separate traverse belts 48- and respectively. Traverse belt 48 has a plurality of yarn engaging fingers 49 fixed at predetermined intervals along one edge thereof and projecting outwardly from one edge thereof. In similiar fashion belt 50 has a plurality of evenly spaced, yarn engaging fingers or guides 51 aflixed thereto in an arrangement corresponding to that of belt 48. In addition to engaging pulley 44a, belt 48 is also engageably sup ported by a pair of idler pulleys 52m and 52b which are 40 rotatably mounted on the lower sections of offset stub shafts 53, 54 respectively, the stub shafts, in turn, being afiixed to platform 40. A span 55 of belt 48 which stretches between pulleys 52a and 52b extends in a path substantially parallel with the axis of said package P and slightly spaced therefrom as best seen in FIG. 2. Traverse belt 50 is also engageably supported by a pair of idler pulleys 56a and 56b which are rotatable on the upper sections of offset stub shafts 53, 54 respectively (see FIG. 8). A span 58 of belt 50 extends between pulleys 56a, 56b, the span running substantially parallel with and above the span 55 of belt 48. A pair of guide pulleys 59, 60 are rotatably mounted on posts 61, 62, respectively, supported from platform 40. Said guide pulleys 59, 60 engage traverse belts 48 and 50 respectively and serve to maintain a desirable level of tension therein as well as to assist in tracking the belts. In order that the belts 48, 50 may be moved in synchronism, belts 48, 50 may have the usual teeth (not shown) formed therein and the several pulleys may be formed as timing sprockets provided with complementary teeth (not shown) for mating with the timing belts.

For driving the traversing belts 48, 50 there is provided a drive belt 63 which is engageably receivedaround a pulley 64 fixed to motor output shaft 28. The drive belt 63 extends between pulley 64 and an idler pulley 76 which is rotatably mounted on a stub shaft 77 suitably supported on platform 40. Intermediate pulleys 64 and 76, the belt 63 engages driven pulleys 46a and 4612, both of which are fixed on the rotatable shaft 38. By virtue of the engagement of drive belt 63 with pulleys 46a and 46b the belt 63 serves to drive traverse belts 48 and 50' as the drive belt is operated in response to energization of motor M. Thus, according to the construction of the elements of the winding machine 12 illustrated in FIG. 2, it is evident that motor M serves simultaneously to drive traverse belts 48 and 50 and yarn package P. It will further be appreciated that the various pulley ratios can be altered to achieve any desirable relationship between the traverse belts on one hand and the yarn package on the other thereby to wind the yarn at a preferred helix angle.

Viewing FIG. 2 it will be observed that the yarn package P is suitably held in rolling engagement against a roller bail 78 rotatably mounted in bearings 80 which are integral with housing 42. As seen in FIG. 1 said yarn package is rotatably supported on a swing arm 82 (removed in FIG. 2) having a pivot 84 whose axis is aligned with that of motor output shaft 28. Upon growth of the yarn package P, spindle 26 recedes from roller bail 78 along an arc, the center of which is located on the axis of pivot 84, whereby said package retains its relationship with drive shaft 28 regardless of the size to which it grows.

Turning again to FIGS. 1, 4 and 5, intermediate of the guide 16 and package P, strand Y passes between a face plate 86, forming a side wall of housing 42, and a retainer plate 88 separated therefrom. Face plate 86 is provided with a pair of parallel, spaced-apart slots 90 positioned to receive therethrough the yarn engaging fingers 49 and 51, as illustrated in FIG. 5. Similarly, the retainer plate 88 is provided with a pair of finger receiving slots 92 parallel to and coextensive with said slots 90. In one embodiment (see FIGS. 4 and 5), a yarn engaging rod 94 is secured to face plate 86 as by clamps 96 and extends substantially parallel to and below slots 90 and 92.

In another embodiment (see FIG. 6), rod 94 has been replaced by a yarn regulator indicated generally at 98. Regulator 98 is mounted to face plate 86 by means of screws 100 and includes a base member 102 having a fluid manifold 104 extending substantially the length thereof. At each end of regulator 98, a guide finger 106 is secured to the base member 102 by said screws 100 but is separated from the base member by means of a spacer 108 to thereby define a yarn receiving channel 110. Spacers of various size can be employed according to the diameter of the yarn strand being wound. The fluid manifold 104 is connected to a source of pressurized fluid such as compressed air (not shown) by a conduit 112. A fluid entry port 114 is formed in the wall of base member 102 adjacent the spacer 108 at each end of regulator 98 to connect manifold 104 to channel 110 whereby pressurized fluid is directed from generally each end of the channel toward the center of the regulator. The yarn engaging rod 94 provides suitable yarn control particularly at the lower yarn winding speeds, for example, those less than 3000 yards per minute. The object thereof is to urge the yarn against the interior of plate 88 as seen in FIG. 5 while momentarily restraining the yarn at the instant of yarn reversal as when the strand Y is released from a finger 49 to be subsequently engaged by an oppositely travelling finger 51. The rod 94 advantageously limits motion of the yarn between traverse mechanism 22 and guide 16 to control ballooning and vibrations therein by frictional engagement of the running yarn therewith. Also, as seen in FIG. 5, the rod causes the yarn to run against plate 88 to insert additional tension control on the yarn.

The yarn regulator 98 serves effectively at the higher windings speeds, for example those greater than 3000 yards per minute to control the winding yarn. The channel 110 of regulator 98 is positioned in the line of traverse of the yarn strand Y. Hence, as the yarn strand Y is traversed into one side of said channel, and is transferred from one yarn engaging finger to another, the stream of pressurized fluid issuing forth from manifold 104 through fluid entry port 114 into said channel 110 impinges on the yarn strand intermediate of guide 16 and the yarn engaging fingers 49, 51. The fluid stream serves to counteract and substantially reduce the balloon which tends to form in the strand by reason of its inertia upon its reversal of direction. A primary advantage thereof resides in improved tension control of the winding strand which in turn results in a package having improved redraw characteristics. Fur- 6 ther, it will be appreciated that as the yarn is positioned in channel it is caused to contact the interior of plate 88 in the same fashion as already described in connection with rod 94, to thereby control the movement of yarn Y.

Another feature of the invention herein resides in the provision of auxiliary yarn engaging fingers 116, 117 extending radially from the periphery of pulleys 52a, 5612 respectively.

FIGS. 7A-7 G illustrate in detail the action of the yarn engaging fingers 49, 51 in cooperation with an auxiliary finger on one of the pulleys 52a, 56b, and for illustrative purposes the action at the left-hand end of package (viewing FIG. 2) is detailed in FIGS. 7A7G. It will be appreciated that the same steps in yarn reversal would similarly occur at the opposite end of the package. Thus, in FIG. 7A a strand of yarn Y is depicted as it approaches the end of its traverse to the left, said strand being traversed across the peripheral surface of package P by a finger 51 on span 58 of belt 50. As shown in FIG. 7A auxiliary finger 116 on pulley 52a is positioned immediately in advance of finger 49 on belt 48. In FIG. 7B the yarn is seen to have advanced further to the left under the control of finger 51 with fingers 49 and 116 moving theretoward in a clockwise direction for engagement therewith. In FIG. 7C, yarn Y is shown emerging from the tip of finger 51 while in FIG. 7D the auxiliary finger 116, is shown passing under the yarn to be in a position forward of the reversal movement of the yarn. As seen in FIG. 7B the yarn is snared by auxiliary finger 116 which retards said strand momentarily against further movement toward the right, i.e., the center of the package, which movement may otherwise occur under the tension in the strand. Auxiliary finger 116 continues to engage the strand Y until finger 49 advances a sufficient distance to move into the firm engagement therewith as seen in FIG. 7G. During its rotational movement, fingers 116 and 117 are driven at a speed to permit traversal of the yarn inward from the end of the package at a rate of speed corresponding substantially to the rate at which the yarn is traversed across the remainder of the package by either of the fingers 49 or 51. Hence, a package of highly desirable characteristics free of the usual high ends is Wound. In FIG. 7 G, auxiliary finger 116 has been rotated to a position completely out of engagement with strand Y and finger 49 is in complete command to traverse said strand to the opposite end of the package as seen in FIG. 7G whereat a similar yarn transfer and reversal operation will occur.

It will be appreciated that during the transfer operation described, the strand Y is continuously controlled by means of one of the cooperating yarn engaging fingers 49, 51 in cooperation with auxiliary finger 116. Immediately upon. its release from, say, finger 51, the strand Y is engaged by auxiliary finger 116, which itself is rotated out of position as soon as finger 49 assumes the necessary attitude to successfully traverse said strand across the surface of the package. Further, it will be appreciated that by the use of timing belts in combination with timing pulleys, and by virtue of the disposition of each of the fingers 116, 117 on its respective pulley, the cooperation of the yarn travers ng fingers 49, 51 and auxiliary fingers 116, 117 are mamtained in a carefully time relationship so that yarn reversal occurs at the same point on the package each time. Additionally, it Will be understood that the spacing of the yarn traversing fingers is such that as an active finger traverses the yarn across the package in one direction there will be no movement in that parallel path in the opposite direction of another finger which might interfere with the traversal of the yarn. That is to say, the passing zones for oppositely moving fingers should be at the points of yarn reversal as clearly illustrated in FIGS. 7A through 7G, although in the interests of providing longer belts additional fingers may be mounted thereon so long as their spacing does not permit their passing in the active traversing zone between pulleys 52a, 56a and pulleys 52b, 56b.

While the disclosure herein has been restricted to preferred embodiments of the invention, these are not for the purpose of limiting the invention but for description alone. The invention is to be limited only by the scope of the claims appended hereto.

What is claimed is:

1. A winding machine comprising, a winding unit for axially mounting a core to wind thereon a strand advancing from a supply source, means for guiding the strand onto the core between axially spaced first and second reversal zones to form a package and including at least first and second yarn traversing elements, means for moving said first and second elements in opposite directions generally parallel to the axis and between said zones and including first and second belt spans having mounted thereon said first and second traversing elements, respectively, first and second guide pulleys for receiving said first and second belt spans, respectively, said pulleys being disposed in said first and second said zones, respectively, each of said elements being operable to receive the strand at the associated one of said zones and to release the strand at the other of said zones for reception by the other of said elements, and auxiliary means operable in the Zones for engaging the strand upon release by one of said elements for engagement by the other of said elements for controlling the reversal motion of said strand in said zone, said auxiliary means comprising strand engaging member, one on each of said first and second pulleys, for engaging the strand.

2. A yarn winding machine comprising, a rotatable spindle, first means for traversing an advancing strand of yarn in a first direction axially of said spindle, second means for traversing the yarn in a second direction axially of said spindle, traversing of the yarn by said first and second means serving to distribute the yarn to wind a yarn package, guide means for directing the paths of said first and second means wherein the yarn is released by one of said first and second means in a zone corresponding within a first end of said package for engagement with the other of said first and second means to reverse the direction of traverse of the yarn to deliver it to a second end of said package, elongated means including a channel through which said yarn advances, said channel extending in a path generally parallel to the axis of said spindle, and means for delivering pressurized fluid into said channel for controlling the reversal motion of the yarn at the first and second ends of said package.

3. The combination as set forth in claim 2 wherein said first and second means includes endless spans, each having at least one yarn engaging member thereon, and said guide means includes a first and second guide wheel for each of said first and second spans, the respective first and second guide wheels for each said span being arranged to provide a path of movement for each said span and its associated yarn engaging member from a yarn receiving position relatively near said package to a yarn disengaging position relatively distant from said package.

4. The combination as set forth in claim 3 wherein said channel is operable to position said yarn for engagement by the yarn engaging member on one of said first and second spans when released by the yarn engaging member on the other of said spans.

5. The combination as set forth in claim 4 including auxiliary means for controlling the movement of said yarn during transfer thereof between the yarn engaging members on said first and second spans.

6. The combination as set forth in claim 5 wherein said auxiliary means includes at least one yarn engaging finger operable in a zone corresponding generally to each end of said package.

7. The combination as set forth in claim 6 wherein each said finger is mounted to engage the yarn during the interval after release by one of said yarn engaging members and prior to the engagement of the yarn by a further one of the yarn engaging members.

8. Apparatus for winding advancing yarn comprising, a rotatable take-up unit for winding the yarn into a package, an elongated element situated proximate to said takeup unit, said element having an elongated passage formed therein extending generally parallel to the axis of said takeup unit, said passage having opposing side Walls spaced apart a distance to permit free movement of the yarn therebetween, traversing means including at least two yarn engaging members arranged for movement longitudinally of said passage in opposite directions, said members being disposed to extend across said passage between said opposing side walls during their longitudinal movement, and means for moving said members longitudinally of said passage in opposite directions to thus traverse the yarn axially of said take-up unit and distribute the yarn thereon to wind a package, the yarn being constrained between said opposing side walls and on one of said yarn engaging members during traversal movement of the yarn from end to end of said package.

9. Apparatus as set forth in claim 8 including tensioning means operable to maintain the yarn under substantially constant tension during winding onto said package.

10. Apparatus as set forth in claim 9 wherein said tensioning means includes means for emitting fluid pressure against the yarn.

11. Apparatus as set forth in claim 9 wherein said tensioning means includes an elongated rod engageable with the yarn.

12. Apparatus as set forth in claim 8 wherein said traversing means further includes first and second endless spans movable in opposite directions relative to said takeup unit, a yarn engaging member being mounted on each said span for traversing the yarn in opposite directions from one end of the package to the other, each said yarn engaging member extending across said passage during its yarn traversing movement.

13. Apparatus as set forth in claim 12 wherein each said endless span is arranged to move its associated yarn engaging member from a yarn receiving position relatively near said package to a yarn disengaging position relatively distant from said package.

14. Apparatus as set forth in claim 13 wherein said passage is operable to position said yarn for engagement by a yarn engaging member on one of said first and second spans when the yarn is released from engagement with a yarn engaging member on the other of said spans.

15. The combination as set forth in claim 14 including auxiliary means for controlling the yarn during transfer thereof between said first and second means.

16. The combination as set forth in claim 15 wherein said auxiliary means includes at least one yarn engaging finger operable in a zone corresponding generally to each end of said package.

References Cited UNITED STATES PATENTS 2,741,443 4/1956 Klein.

FOREIGN PATENTS 642,286 6/1962 Canada. 972,440 8/1950 France. 1,140,629 3/1957 France.

STANLEY N. GILREATH, Primary Examiner US. Cl. X.R. 242158 

